imx8m(n): garbage on serial line

[Heiko Thiery]

Hi,

Am Fr., 10. Juni 2022 um 15:00 Uhr schrieb Fabio Estevam <festevam at gmail.com>:
>
> Hi Heiko,
>
> On Fri, Jun 10, 2022 at 7:29 AM Heiko Thiery <heiko.thiery at gmail.com> wrote:
> >
> > Hi,
> >
> > I just rebased my pending patch for adding support for the NXP imx8mn
> > ddr3l evk board. When applying on the current master I see some
> > garbage on the serial input.
> >
> > Can anyone confirm that behavior or is it just here?
>
> Just tried booting on a imx8mn ddr4 evk and such a problem does not happen:
>
> U-Boot SPL 2022.07-rc4-00007-g57bd363de7 (Jun 10 2022 - 09:42:49 -0300)
> SEC0:  RNG instantiated
> Normal Boot
> WDT:   Started watchdog at 30280000 with servicing (60s timeout)
> Trying to boot from BOOTROM
> image offset 0x8000, pagesize 0x200, ivt offset 0x0
> NOTICE:  BL31: v2.7(release):v2.7.0
> NOTICE:  BL31: Built : 09:42:28, Jun 10 2022
>
>
> U-Boot 2022.07-rc4-00007-g57bd363de7 (Jun 10 2022 - 09:42:49 -0300)
>
> CPU:   Freescale i.MX8MNano Quad rev1.0 at 1200 MHz
> Reset cause: POR
> Model: NXP i.MX8MNano DDR4 EVK board
> DRAM:  2 GiB
> Core:  139 devices, 22 uclasses, devicetree: separate
> WDT:   Started watchdog at 30280000 with servicing (60s timeout)
> MMC:   FSL_SDHC: 1, FSL_SDHC: 2
> Loading Environment from MMC... OK
> In:    serial at 30890000
> Out:   serial at 30890000
> Err:   serial at 30890000
> Net:   eth0: ethernet at 30be0000
> Hit any key to stop autoboot:  0
>
> Also tried booting on a imx8mm evk and did not see the serial garbage either.
>
> Not sure why this happens on the imx8mn ddr3 evk and on the
> kontron_sl_imx8mm though.

Yes, this is strange.

>
> None of the boards I have physical access show the problem. The
> Kontron board  have remote access only,
> so not very easy to run git bisect.
>
> Are you able to bisect it with the kontron_sl_imx8mm board?

Unfortunately only next week again. But I will try on my imx8mq later.

--
Heiko